The invention relates to electronic instrument enclosures that are located with utility meters outside of a building in underground enclosures.
In moderate climate zones, utility meters are located in subsurface enclosures in areas near residences or other dwellings. Such enclosures are referred to as xe2x80x9cpits.xe2x80x9d An example of such enclosure is illustrated in Haase et al., U.S. Pat. No. 1,781,280.
In Edwards et al., EPO Publication No. 0 252 184, meter data is transmitted from a utility meter in an underground pit to an in-ground electronic coupling circuit and then to an electronic collection unit carried by a meter reading person. Scuilli, U.S. Pat. No. 4,758,836, shows an electronic metering unit which uses the inductive coupling method of the metering unit of Edwards et al.
Besides inductive coupling system, radio frequency transponder systems have also been known. Examples are illustrated and described in Cerny et al., U.S. Pat. No. 5,298,894, issued Mar. 29, 1994, and assigned to the assignee of the present invention. In these systems, a receiver/transmitter, and an associated antenna are enclosed in one or more sealed enclosures which are located in a larger pit for the water meter. When the transponder is interrogated by a signal, it returns a radio signal to a collection unit, either hand-held or carried by in a vehicle, where the radio signal can then be decoded to extract the meter data.
A primary issue concerning all remote meter systems, whether used in pit installations or elsewhere, is their resistance to weather, and to submersion in the event that the pit fills with water. Therefore, a primary object of the invention is to provide a device that is resistant to environmental conditions in its operating environment.
Typically, the data storage device is powered by one or more batteries, which must also be contained in a sealed enclosure. For an example of a prior battery assembly, please refer to Karsten et al., U.S. Pat. No. 5,476,731, assigned to the assignee of the present invention.
Therefore, another object of the invention is to provide for battery replacement in the field without adversely affecting the environmental protection of the electronics in the assembly.
As with other electronic devices, there is also a desire to make the devices smaller in size, lower in the cost of manufacture, and easier to service in the field.
The invention is provided in an improved battery enclosure which can also be enclosed within an outer enclosure but removed, in the event that the battery must be changed, without affecting the environmental protection of the other portions of the assembly.
The invention provides a fully remote meter reading system with weather-resistant features that permit installation of the transponder unit in outdoor underground enclosures.
The invention provides a unit of reduced size and weight, and yet provides the weather resistance and operating features of prior units.
The invention also provides a unit having advantages in its assembly and manufacturing.
Other objects and advantages, besides those discussed above, will be apparent to those of ordinary skill in the art from the description of the preferred embodiment which follows. In the description, reference is made to the accompanying drawings, which form a part hereof, and which illustrate examples of the invention. Such examples, however, are not exhaustive of the various embodiments of the invention, and, therefore, reference is made to the claims which follow the description for determining the scope of the invention.